1. Field of the Invention
The present invention relates to a semiconductor fabricating method. More particularly, the present invention relates to a method of forming a gate.
2. Description of the Related Art
Because a conventional gate is made of polysilicon with a large grain size, the surface of the gate is rough. The rough surface of the gate causes scattering of a deep ultra violet ray. The scattering of a deep ultra violet ray causes difficulty in controlling a critical dimension (CD) of the gate. Therefore, the uniform critical dimension of gate is rarely achieved.
Another problem that occurs in the conventional gate is a channeling effect. That is, boron ions in the gate easily gather at a boundary between the gate and the gate oxide layer. Once the amount of gathered boron reaches a specific number, boron ions easily penetrate into the gate oxide layer. The device failure is occurred when the boron ions penetrate into the gate oxide layer.